Lifting jack



Dec.- 4 1923.

J. A. MORRISON LIFPING JACK l Filed Feb. 2l 1921 5 Sheets-Sheet 1 Illlmlll J. A. MORRISON l LIFTING JACK Filed Fb 21. 1921 {Sheets-Sheet 2 Dec. 4 1923.

Dec.. 4 l, l1923. 1,416,096

J. AQ MORRISON LIFTING JACK I Filed Feb. 2l. 1921 s sheets-sheet s mum Patented Dec. 4, 1923.

LUNITED STATES JOHN A. MORRISON, F MANSFIELD, OHIO. l

LIFTING JACK.

.Application filed February 21, 1921. Serial No. 446,713.

To all 'whom t ,may concern.'

Be it known that I, JOHN A. MORRISON, a citizen of the United States. residing at Mansfield, in the county of Richland and State of Ohio, have invented a new and useful Lifting Jack, of which the following is a specification.

This invention relates to lifting ,j acks and more particularly to that type ofjack espeL cially adapted for automobile use,and is an improvement over my allowed a plication for improvement in lifting jacks, erial No. 369,826, filed March 29, 1920. I The objects of the present invention are to provide a jack of the character illustrated and described in my prior application above referred to in which a two part lifting bar is provided, one part being arranged to be raised independently of the other part to a predetermined height after which the two parts are automatically locked together and raised to the maximum height, means being provided for positively preventing one part of the lifting bar from being moved until the other part has reached a Vpredetermined height, other objects being to generally improve and simplify the construction of lifting jacks of this general character.

With these objects in view the invention consists in the novel construction and arrangement of parts, hereinafter described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of construction may be made within the scope of the appended claims,

without departing from the spirit or sacricing any of the advantages of the inven.

tion.

The invention thus set forth in ,general terms is illustrated in the accompanying drawings forming part hereof in which- Figure l is a side elevation of a lifting jack embodying the invention showingthe liftingv bar in lowered position, a part of the gear housing being broken away for the purpose of illustration.A

Fig. 2 is a front elevation of the same.

Fig. 3 is a section on the line 3 3, Fig.` 2.

Fig. 4 is a section on the line 4 4, Fig. 3.

Fig. 5 is a `front view of the jack with the housing broken away, the driving worm being shown in section. Y

' Fig. 6 is a top plan view of the jack.

Fig. 7 is a section similar to'Fig. 3, showing the lifting bar in the raised position.

Fig. 8 is a section similar to Fig. 4, showing the lifting bar in the raised position.

ig. 9 is a detached perspective viewy ofthe channel member of the lifting bar.

Fig. 10 isa similar view of the rack bar member of the lifting bar, and

Fig. 11 is a detail perspective View upon aV larger scale of the locking key,by means of which the two members of the lifting bar are automatically locked together.1

A practical embodiment of thefinvention is disclosed vin the accompanying drawings' forming a part of this specification in which similar numerals of reference indicate corresponding partsA throughout the several views. ,y Y

The standard within which the liftingKV mechanism is carried comprises a housingfl, the lower portion of which is preferably skirted as shown at 2to provide a more stable support for theI jack, the basejof the` housing being closed asv shownY at .3 to pre-V vent dirt and dust from `entering the .hous-` ing and coming into ,contact with the working parts of the lack.

The lifting bar of the ack comprises two members, a channel shapedrack member 4 being vertically slidably mounted lwithin the housing and provided with a T-shaped verti` cal slot 5 withinwhich is slidably mounted the T-shaped rack bar 6, the bar 6v being normally telescoped within the p channel member 4 when the jack is in the lowered position as shown in Figs. l to 5 inclusive.

In this position the teeth` of the rack bar 6 meshes with lthev teeth of. the pinion. v7, whichl pinion is of substantially the width of the channel bar 4 and is fixed upon the shaft 8 upon which shaft is also fixed the worm gear 9 meshing with the worm l0, a'

suitable gear housing ll being providedto accommodate the worm gear and worm.

The upper end portion of the rack channel is provided with the cut-out portion 7"3L within which the pinion 7 is located when the rack channel is. in the lowered position,g the pinion thus being normally out of mesh with the teeth of the rack channel'until the rack bar has passed to the limit of'its move#V ment with relation to the 'rack channel.l

A ball bearing 12 is preferably provided upon the shaft 13 of the wormto provide for a free movement ofthe worm,l the extremity of said shaft being squared as shown at 14 for the. reception of the socket oi the usual handle by means of whichl the worm may be operated.

The channel rack is normally held in the i lowered position, against movement by the upward movement of the rack bar. by means of the spring pressed plunger 15 which is mounted within the boss 16 formed upon the housing, a cap 17 being screw threaded upon said boss and containing the spring 18, the inner extremity of the plunger being tapered as. shown at 19 and normally seated inv the aperture 20 in the channel rack 4.

The aperture 2O communicates with Va vertical groove. 21 in the. channel rack 4, said groove terminating at its upper end in the shoulder 22. The rack bar 6 is provided with a lug` 23 having. a tapered portion 24l at its. upper end, said lug being slidably received within the groove 21 and arranged to engage the tapered end vof the. plunger 15 whenY the-bar 6y reaches theupper limit of its. movement withV relation to. the channel member 4, moving the plunger out of engagement wit-h the member 4, the lug 23 engaging theV shoulder'22 in the channel member, causing the channel member to. be moved with. the bar 6 until the teeth of the channel` member are brought into engagement., with the pinion 7.

A locking key 25V is slidably mounted in the passage 26. provided near the upper end of the channel member, a leaf spring 27 carried by said. channel member normally holding said locking key in engagement with the rear face of the rack bar. Ears 28 are providedupo-n thel rear end of the. locking key and are normally located in the inc-lined grooves 29., provided in the upper portion of the housing 1, when the channel member is in the, lowered position.

As the channel member is pickedA up by the rack bar, as above describechand moved upwardly therewith, the key 25, riding iny the inclined grooves 29, will be moved into the notch 3()V formed inthe rear face of the rackA bar near the lower end thereof, they spring 27 holding the locking key in this n positionas the channel member` 4 israised above the housing 1, thus locking the rack bar and rack channel together. Y Y

Ahead 31V provided with a Vcorrugated ory serratedupper surface. 32, isloosely mount-l ed .upon the. shank 33 at theupper end of the rackjbar 6 by means of a pin 34, this f head. being provided for engagement with the under surface of;` the automobile axle or other pari; of the. automobile beneath which the jackmay be conveniently placed for the purpose ofv raising the automobile.

Fromfthe.v above, it will be. evident that by rotation.otheworm 10, in. the-.proper dillectionrthepinio-n 7. will, be rotatedzin a direction to; raiseatlierackban 6.'.-to.the. limitof its movement with reference to the channel. member 4 at which time the channel member will be pickedl up by the rack bar and raised therewith, 'the two members of the lifting bar being automatically locked together at this point and the teeth upon the rack channel being brought into engagement with the pinion, which continues to raise the rackY channel, and with it the rack bar locked thereto, to the upper limit of movement of the rack channel-,thus providing a lifting span substantially doublethe span ordinarily obtained with a lifting bar formed. of a single member.

When it is desired to lower the jack, thev worm is rotated in the oppositedirection, the lifting bar being lowered until the. channel member is moved intov its lowered position at which time the. rack bar'isautomatically unlocked from the channel member andthe teeth upon the rack bar are. moved.` into engagement with thepinionlwhich continues the lowering of the racky bar tothe: initial position.

It will be seenthat the plunger lorms av positive means for preventing thev channel. member from being accidentally raised by the upward movement of theV rack barV until the rackbar has reached the upper limitof its relative movement, at which time the plunger 15- isY automatically disengagedl from thev channel member, allowing; the channel member to be moved upwardly with therack bar. l

I claim 1. A lifting jack comprising a standard, a liftingbar verticallyy movable within the standard and comprising aI pair of. rackmembers, lifting means for alternate engagement with eac-h of: said rack members for moving one of said rackl membersindependently of the other, a spring pressed plunger within the housing for holding the other rack member against movement until the first rack. member has reached` the.y limit` of'itsupward movement with relationto the second rack member, and means for automatically locking said n rackV members together'at this point the lifting means moving both of said rack members after they are lockedV together.

2. A lifting jack comprising.aistandard,

Ya lifting. bar mounted for. vertical movement within` the standard and comprising` a Vrack channel and a` rackfbar mounted" forAA ment with the pinion after the plunger has been released and means for automatically locking the rack bar and rack channel together at this point.

3. A lifting jack comprising a standard, a lifting bar mounted for vertical movement Within the standard and comprising a rack channel and a rack bar mounted for vertical movement therein, .a pinion in the stand ard normally engaging the rack bar said rack channel provided With a socket near its upper extremity, a shoulder upon the rack channel above said socket, a spring pressed plunger mounted in the standard and arranged to be normally seated in said socket, a lug upon the lower portion of the rack bar arranged to engage said plunger to release the same from the rack channel and to engage said shoulder to lift the rack channel into engagement with theV pinion and means for automatically locking the rack bar and the channel together at this point.

In testimony that I claim the above, I have hereunto subscribed my name.

' JOHN A. MORRISON. 

